An autostereoscopic system particularly suitable for the shutter described in this document is the time-multiplexed system described in PCT application PCT/IB2005/001480. However, the shutter is suitable for any application where high switching speeds and high contrast are required.
An autostereoscopic or 3D display can be implemented by synchronising a high frame rate screen for displaying a two dimensional image with a fast switching shutter. If each frame on the screen is synchronised with a corresponding slit, and the images and slits are run at sufficient speeds to avoid flicker, typically 50 Hz or above, then a 3D image can be created.
FIG. 1 shows the principle of an autostereoscopic display. As shown in the diagram, when the screen is viewed through one open slit of the shutter, each eye sees a different part of the screen, and hence each eye sees a different part of an image displayed on the screen. Image 1 is displayed on the screen whilst slit 1 is open. Similarly slit 2 is open when frame 2 is displayed. By repeating the process sufficiently fast such that each slit is perceived as flicker-free the entire shutter will represent a window into a 3D scene. It is assumed that the individual images displayed represent the correct perspectives through each slit. By way of example, given a flicker rate of 60 Hz, a 12 slit shutter requires a display capable of a refresh rate of 720 Hz.